Francisco Liriano has reemerged as an elite pitcher this year and his latest masterpiece came Friday night against the Braves, with 11 strikeouts and zero walks in eight innings of one-run ball. His gem versus Atlanta marked the second straight start in which Liriano has allowed just one run while racking up double-digit strikeouts, and overall this season he's 6-3 with a 2.90 ERA and 87-to-21 strikeout-to-walk ratio in 80.2 innings spread over 12 starts.

Now four years removed from Tommy John surgery Liriano has clearly re-established himself as an ace, but because he was the ace prior to going under the knife the temptation will always be there to compare what he's doing now to the 2006 version that eviscerated the league as a 22-year-old rookie. Thanks to abundance of information available at Fan Graphs, we can get a pretty good idea of how Liriano in 2010 stacks up to Liriano in 2006.

Liriano in 2006 threw his fastball an average of 94.7 miles per hour, but his velocity has dipped to 93.5 miles per hour this season. While that still ranks seventh in the league, a decline of 1.2 miles per hour is a significant drop in velocity. However, despite Liriano's fastball being slower he's thrown it 16.2 percent more often and the pitch has also been more effective, rating 0.50 runs above average per 100 offerings compared to 0.13 runs above average per 100 in 2006.

In other words, Liriano's fastball has gotten worse but he's gotten better at throwing it, which is natural for a pitcher as he gains more experience and also a credit to the work he's done on the long road back from surgery. Obviously it would be great if Liriano threw 95 mph again, but having better command of the pitch at 93.5 mph can actually be even better. Now let's take a similar look at his slider:

Surgery cost Liriano even more velocity on his slider than his fastball, with the pitch going from an average of 87.7 mph in 2006 to 85.0 mph this year. Not only did his 87.7 mph slider lead the league in 2006, no one else even cracked 87.0. This year his slider velocity is 13th in the league and unlike with the fastball he hasn't been able to compensate by throwing it better. He's relied on the slider 13.2 percent less and the pitch has been 21.9 percent less effective.

Of course, less effective is a relative term. His slider has gone from +3.47 runs per 100 pitches in 2006 to +2.71 runs per 100 pitches this year, which is a big drop. Yet even at 21.9 percent less effective than it was before surgery Liriano's slider has been the second-best in the AL. That shows just how devastating his slider was in 2006, but also that, as Chipper Jonesput it after facing him Friday, he still throws "some disappearing" and "Randy Johnson-type" sliders.

Liriano's changeup was underrated in 2006 as everyone focused on his mid-90s fastball and ridiculous slider, but it ranked as one of the best in the league at +2.82 runs per 100 pitches. Since coming back from surgery Liriano's changeup velocity has actually risen by 1.3 mph, but that's not a good thing and when combined with a 1.2 mph decline in fastball velocity equals a much less effective weapon. In fact, his changeup has gone from great in 2006 to bad in 2010.

In terms of individual pitches, Liriano's fastball is slower but ultimately more effective, his slider is slower and less effective but still an incredibly dominant offering, and his changeup is faster but significantly less effective. Now let's move on to Liriano's actual results with a year-to-year comparison of his ERA, Expected Fielding Independent Pitching, strikeout rate, walk rate, and ground-ball percentage:

Those stats are all more or less what you'd expected based on the individual pitch changes. He's lost one strikeout per nine innings and has induced 11 percent fewer ground balls, which makes sense given the drops in velocity and slider ridiculousness. However, his walk rate has remained constant at 2.4 batters per nine innings, which can seemingly be linked to Liriano's improved fastball command canceling out the decline in raw, blow-it-past-everyone stuff.

What made Liriano so amazing in 2006 is that he combined an incredible number of strikeouts with tons of ground balls, which is the perfect recipe for a pitcher. Surgery has cost him about 10 percent of both his strikeouts and ground balls, but Liriano still ranks third in the league in strikeout rate and 12th in ground-ball rate. In terms of overall effectiveness, he's gone from a 2.16 ERA and 2.35 xFIP in 2006 to a 2.90 ERA and 2.95 xFIP this season.

Liriano has actually thrown 13.3 percent fewer pitches in the strike zone (ZONE) this season, which perhaps could be chalked up to his no longer being able to simply overpower everyone with strikes. Opponents are swinging (SWNG) at basically the same number of pitches, hacking at 48 percent in 2006 and 47 percent this season, but they're making contact (CONT) on those swings 15.4 percent more often this year.

On pitches inside the zone opponents are swinging (Z-SW) at the same rate as 2006, but are making 15 percent more contact (Z-CN). On pitches outside the zone opponents are swinging (O-SW) 17 percent more often and also making 55 percent more contact (O-CN). I'm not smart enough to know for sure, but it seems like the slider going from ridiculous to merely excellent and the changeup going from excellent to bad could explain the swing and contact changes.

Add it all up and Liriano clearly isn't the same pitcher he was before elbow surgery. His velocity is down, his slider and changeup aren't as good, he's getting 10 percent fewer strikeouts and ground balls, and hitters are having a much easier time making contact against him on pitches in and out of the strike zone. He's also relying less on his slider and more on his fastball, likely due in part to the injury risk of the slider and in part to his improved command of the fastball.

It seems clear that the phenom who toyed with the league in 2006 is simply gone forever, but the good news is that Liriano was so spectacularly awesome then that even this post-surgery version with obvious declines in numerous areas is one of the elite pitchers in all of baseball. His combination of strikeouts and ground balls still ranks among the best in the league and his raw stuff is still capable of overpowering hitters, as the Braves saw first hand Friday.

Oh, and the other good news? F-Bomb 2.0 is still five months from his 27th birthday.

Great article. To the previous comment, the 55.3 GB% in 2006 going down to 49.1 GB% in 2010 is actually a little over an 11% decline (11.2% I calculate). 11% of 55.3 is about 6.1 and if you subtract that from the 55.3 you get 49.2.

How much of a difference would it make from here if Liriano could lose 2-3 MPH on his changeup? It seems like most of the effort so far has (sensibly) been on re-establishing his fastball and slider, but maybe it’s time to take a look at the change. Far be it from me to say I know much about pitching, but that seems like it ought to be fairly easy compared with what he’s done so far.

Liriano-2006 was a grand total of 14 starts from mid-May through the end of July. Just less than half a season. Left to pitch for a full season without injury, the chances are he would have regressed a bit from that anyways.

Liriano’s changeup is evolving. He’s starting to get better command with it, and he’s starting to get it to bend to the left, almost like a screwball. With his fastball going about 93mph and his change coming in at about 83mph, a ten mph difference is good.

Oh, and I noticed something else: Liriano throws his change and his slider at the same spot outside to right handed batters. The slider bends right and down, winding up half a foot off the ground when Mauer catches it. His change, thrown towards the same spot, bends left and slightly down, winding up just outside and about a foot off the dirt when Mauer catches it. The difference in location of those two pitches, initially thrown at the same spot yet ending two feet apart, must be very difficult for a batter to predict. To me, that means Liriano should throw his change and his slider about the same number of times, in a random sequence.

I think you are missing one key stat from your analysis: The “who the heck is he factor”

in 2005 Liriano had about 23 innings pitched in relief and 4 starts. It wasnt until 2006 that Liriano was rolled out into primetime starting mode. In other words, noone in the AL had faced him or those devistating combination of pitches. The batters, scouts, and coaches had no real idea how to hit him or what to wait on.

2008-2009 were years plagued by a healing arm, bad teams he got to face in 2008, and 2009 teams knew what to expect (avoid anything with spin outside the zone and wait for the heater or changeup down the middle). He was still getting used to throwing stuff with spin (hence the wildness)

2010 he is now going up against teams, coaches, and scouts who know how he pitches and operates. I think his improved fastball and slider numbers reflect that he is MUCH more of a smarter pitcher than he was in 2006. Liriano now has to not only outduel the batters from a mental standpoint, but he has to throw effective pitches.

It isnt uncommon to see this happen with great rookies when them come up or international players (think Irabu for the Yankees, Okajima for the Sox, Kim Diamondbacks, etc). They often throw lights out until they make their way back through the league (it will be interesting to see how Strassburg does)

Aaron,
How about some time doing an analysis of the Twins record by days of the week under Gardy? This year the Twins are 4-6 on Sundays, which seems to be the day each week he is bound and determined to play the “B” or “C” squad. These have been virtually all day games, as well as the last game of a series.
Conversely, they are 8-1 on Fridays, which is usually the “A” squad, as well as a night game and the first game of a series.
it really is irritating turning on the tv on Sundays to watch them, and then have their worst lineup on the field!